What's more, these results can only speak to the effects of a modest supplementation of omega-3s for patients who, like the subjects, have had a previous heart attack and are now being rigorously treated for heart disease, experts point out.
"These results don't say anything about what omega-3 fatty acids could do for prevention [of a heart attack] or for someone whose heart disease is not as well managed," says Lichtenstein.
Research on the heart-protective benefits of omega-3 supplements remains inconsistent, though some studies show benefit and these supplements are often suggested to patients with heart disease.
Research on the consumption of fish on the other hand, has shown a strong connection between a diet rich in fish and a decreased risk of heart disease and cardiovascular complications such as heart attack or stroke, experts say.
"Every time we try to isolate a nutrient and supplement it we get disappointed," says Lichtenstein, "but we consistently see results with those who eat fish on a regular basis."
One shouldn't "make a conclusion that fish aren't important. In general, those who consume fish versus [those who don't] seem to have less coronary heart disease," agrees Dr. Robert Eckel, professor of medicine at the University of Colorado School of Medicine.
That said, if eating fish a few times a week is hard for you to do, supplements are still advised, Lavie adds, because "very few people eat enough fish."
Similarly, when choosing something to spread on your bread, margarine is still a better choice than butter, doctors say, as long as it is low in saturated fat and trans fatty acids. Though Ornish says if you can trade the margarine for olive or canola oil, even better.
Soybean and canola oil contain ALA and have lower saturated fats than other oils, even olive oil, notes Lichtenstein, so these are a good fat to have in moderation.